Is this a case of UT3 not seeming to pick up the headset, because I've got a couple of friends who recently bought PS3s and are having that problem with UT3.

EDIT: I've had a lookit online, and it seems to be a problem with UT3. Various people are saying the you need to connect the headset to the PS3 prior to starting UT3, and you should hear it link up with the UT3 logo.

EDIT2: And you've got to keep the D-pad pressed for the entire duration of the speaking... which might mean you want to change it to a different button. L2 seems to be a popular choice.